If your Dexcom G7 is not updating on your Apple Watch, the most common cause is a broken connection between your iPhone and the Dexcom app, since your watch usually receives data through your phone. Start by opening the Dexcom G7 app on your iPhone and confirming it shows a live reading. If the phone is current but the watch is stale, restart the watch, check that its complication or app has permission to run, and make sure both devices are on the same Apple ID. Most stale-data problems clear within a few minutes once the phone connection is restored.
The short version: Your Apple Watch almost always gets Dexcom G7 numbers from your iPhone, so fix the phone first. If the phone shows current data but the watch does not, restart the watch, re-add the complication, and confirm Bluetooth and app permissions.
Why does the Dexcom G7 stop updating on Apple Watch?
Your Apple Watch does not read the sensor directly in most setups. The G7 sensor sends data to your iPhone over Bluetooth, and the watch then mirrors that data. So when the watch goes stale, the problem is usually one link in that chain.
The most common reasons are:
- The iPhone lost its Bluetooth link to the sensor, so there is no fresh data to pass along.
- The watch and phone drifted too far apart or lost their own connection.
- A background app refresh or battery setting paused the Dexcom app.
- A recent iOS or watchOS update reset a permission or logged you out.
- A new sensor is in its warm-up period and simply has no readings yet.
Because so many issues start on the phone, always check your iPhone before you blame the watch.
Step-by-step fixes when your watch shows no data
1. Check the iPhone first
Open the Dexcom G7 app on your iPhone. If it shows a current reading, the sensor and phone are fine and the problem is between the phone and watch. If the phone is also stale or shows a signal-loss message, fix that first, because the watch cannot show data the phone does not have.
2. Confirm Bluetooth and stay in range
Make sure Bluetooth is on for the iPhone. Keep the phone within about 20 feet (6 meters) of the sensor, with as few walls and bodies of water (including your own body) between them as possible. Signal loss often happens when the phone is in a back pocket or on the other side of a wall.
3. Restart the Apple Watch
A simple restart clears most stale complications. Press and hold the side button, slide to power off, wait 15 seconds, then turn it back on. Give it a few minutes to reconnect to the phone.
4. Re-add the Dexcom complication or app
If a watch face complication is frozen, remove it and add it back. Press and hold the watch face, tap Edit, remove the Dexcom complication, then add it again. This forces the watch to request a fresh feed.
5. Check Background App Refresh and Low Power Mode
On the iPhone, go to Settings, then General, then Background App Refresh, and make sure it is enabled for Dexcom. Low Power Mode on either device can pause background updates, so turn it off while you troubleshoot.
6. Confirm both devices use the same Apple ID
The watch and phone must be paired and signed in to the same Apple ID for data to sync. If you recently changed accounts or restored a device, this can quietly break the link.
7. Reinstall as a last resort
If nothing else works, restart the iPhone, then delete and reinstall the Dexcom G7 app. You will need your Dexcom login. Note that reinstalling does not require replacing your current sensor.
Is it a real gap or just a new sensor?
When you start a new G7 sensor, it goes through a warm-up period (about 30 minutes for G7) with no readings. That is normal and not a malfunction. A missing number right after a sensor change is almost always warm-up, not a broken watch.
Brief gaps during the day are also normal. CGM systems are designed to catch up once the connection returns, so a five or ten minute gap while your phone was in another room is nothing to worry about. For deeper sensor issues, our Dexcom CGM troubleshooting guide walks through sensor errors and signal loss in detail.
Native Dexcom on Apple Watch vs. a companion app
Dexcom supports showing G7 data on the Apple Watch, and in some configurations the watch can connect directly to the sensor. That native option is great, but it can be limited by watchOS updates, complication quirks, and the fact that it is tied to the official app.
Some people prefer a companion app that pulls from Dexcom Share so the whole household sees the same numbers. If you are not sure how Share fits in, read Dexcom Share vs Dexcom Follow to understand who sees what. For a broader look at wrist options, see our guide to CGM on Apple Watch.
How often should the Dexcom G7 update?
The Dexcom G7 sends a new reading about every 5 minutes. On a working setup, your watch should refresh close to that pace. If your watch face has not changed the number in more than 10 to 15 minutes while the phone is current, treat that as a stale complication and run the fixes above.
Keep in mind that a companion app or a watch complication is a convenience layer. If you feel low or high, always confirm with your primary Dexcom app and, when in doubt, a finger stick. A number on your wrist should support your decisions, not replace your device alarms.
Quick checklist to keep readings flowing
- Keep the iPhone charged, unlocked overnight if possible, and near you.
- Leave Bluetooth on for both devices.
- Enable Background App Refresh for Dexcom.
- Avoid Low Power Mode during the day.
- Update iOS and watchOS, then re-check permissions after each update.
- Restart the watch weekly if you notice frequent freezes.
Frequently asked questions
Why does my Apple Watch show old glucose but my phone is fine?
This is a frozen complication or a paused watch app. Restart the watch, remove and re-add the Dexcom complication, and confirm the two devices share the same Apple ID. Data should return within minutes.
Does the Dexcom G7 need my iPhone nearby to update the watch?
In most setups, yes. The watch mirrors data from the phone, so if the phone is out of range of the sensor or turned off, the watch has nothing fresh to show. Some direct-to-watch configurations exist, but keeping the phone close is the reliable path.
Will reinstalling the Dexcom app end my current sensor?
No. Reinstalling the app does not stop or waste your active sensor. You will log back in and your sensor session continues. Do not remove the physical sensor to fix an app problem.
Is a five minute gap a problem?
No. Short gaps are normal, and the system fills them in once the connection returns. Only long, repeated gaps point to a setup issue worth fixing.
Sugar Sense can pull your Dexcom data through Dexcom Share and show a live glucose number, trend arrow, and high or low alerts right on your iPhone and Apple Watch, plus Care Circle sharing so family can follow along. If you want a simple, reliable second screen for your readings, see how Sugar Sense works.
Safety note: This article is educational and general. A companion app or watch complication never replaces your Dexcom G7 device, its readings, or its alarms, and it can lag or disconnect. Always confirm with your CGM or a finger stick when symptoms and numbers disagree, and make all treatment and medication decisions with your healthcare provider. See our medical disclaimer.
